Touch-responsive tone envelope control circuit for electronic musical instruments

ABSTRACT

In a keying system for an electronic musical instrument in which an individual keyer is operative by the actuation of a corresponding playing key but a keyed tone signal has a predetermined amplitude irresponsive to a key depression intensity, there is provided in combination with the keyer a corresponding circuit means producing a tone signal of an envelope pattern or abrupt buildup and subsequent decay, a socalled attack signal, in response to the key depression intensity. The touch-responsive attack signal gives forth an effective touch-responsive auditory sensation of the total sound.

United States Patent Ryu Hiyama llamamatsu, Japan July 8, 1970 Dec. 7,1971 Nippon Gakkl Seizo Kabushlki Kaisha Hamamatsu-shi, Japan July 12,1969 Japan July 12, 1969, Japan, No. 44/5356 Inventor App]. No. FiledPatented Assignee Priorities TOUCH-RESPONSIVE TONE ENVELOPE CONTROLCIRCUIT FOR ELECTRONIC MUSICAL INSTRUMENTS 15 Claims, 5 Drawing FigsPrimary ExaminerLewis H. Myers Assistant ExaminerUlysses WeldonAttorney-Cushman, Darby & Cushman ABSTRACT: In a keying system for anelectronic musical instrument in which an individual keyer is operativeby the actuation of a corresponding playing key but a keyed tone signalhas a predetermined amplitude irresponsive to a key depressionintensity, there is provided in combination with the keyer U.S. Cl .L 19881/1356, a corresponding circuit means producing a tone Signal of an84/ 8 l envelope pattern or abrupt buildup and subsequent decay, a lnLClG14 14,10 waned attack signal, in response to the key depression Fieldof Search l 36/ 27, tensim The touchqesponsiw attack Signal gives forthan fective touch-responsive auditory sensation of the total sound '5 1l. l c;

| ARY e a. GEIERATOR mg n TOUCH-RESPONSIVE TONE ENVELOPE CONTROL CIRCUITFOR ELECTRONIC MUSICAL INSTRUMENTS BACKGROUND OF THE INVENTION Thepresent invention relates to a touch-responsive tone envelope controlcircuit for electronic musical instruments, and more particularly, to aspecific tone envelope control circuit which can improve the toneenvelope effects in a keyoperated electronic musical instruments such asan electronic organ to provide excellent effects of music being played.

SUMMARY OF THE INVENTION The principal object of the present inventionis to provide a touch-responsive tone envelope control circuit for usewith an electronic musical instrument which easily permits theinstrument incorporating the circuit therein to provide a tone signalhaving an envelope pattern of abrupt buildup with a subsequent decay, aso-called attack signal, in superposed relation with a keyed tone signalof a predetermined amplitude irresponsive to a key depression intensity.

Another object of the present invention is to provide thetouch-responsive tone envelope control circuit which is simple inconstruction, easy and inexpensive to manufacture, and reliable inoperation.

A further object of the present invention is to provide thetouch-responsive tone envelope control circuit including, a plurality ofgate circuits each gating a supplied corresponding tone signal to bekeyed in response to the intensity of depression of a correspondingplaying key.

A still further object of the present invention is to provide thetouch-responsive tone envelope control circuit in which said gatecircuit is adapted to gate a tone signal having a footage different fromthat of a tone signal being applied to the corresponding keyer circuit.

Other object, features and advantages of the present invention willbecome apparent from the following detailed description taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram showing anembodiment of the present invention by one unit.

FIG. 2 is a circuit diagram showing another embodiment of the presentinvention by one unit.

FIGS. 3 to 5 are diagrams for explaining the operations and functions ofcircuits according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Now, same characters andreferences indicate same parts hereunder.

Reference will be made to a touch-responsive tone envelope controlcircuit of the embodiment according to the present invention withreference to FIG. 1, in which a circuit associated with only one key isshown for simplicity of illustration. T, designates an input terminal ofa keyer circuit S, to which a tone signal generated by a correspondingtone source circuit which is easily available is applied. The keyercircuit S is so arranged to be keyed in association with the depressionof a corresponding playing key K arranged on a keyboard of an electronicmusical instrument, and to apply its output at a tone signal outputterminal T L designates a coil grounded at one end adapted to vary theinterlinking fluxes in association with depression of theabove-mentioned key K, of which the other end I is connected through aseries circuit of a rectifying element D and a resistor R to the gate ofa field effect transistor (hereunder referred to by FET), while aconnection point d between the element D and the resistor R is groundedvia a parallel circuit of a capacitor C, and a resistor R,. The outputterminal T, is connected to the drain of the F ET Q. The drain electrodeis connected through a resistor R, to a power source +Vcc. The source ofthe FET Q is grounded through a series circuit of a resistor R and avariable resistor R, in turn, of which the connection point r isconnected through resistors R,

and R to the power source +Vcc and the input terminal T,, respectively.

The usual keyer circuit S is adapted to be keyed only upon depression ofthe key K. By means of the resistors R and R,, the gate to sourcevoltage of the FET Q is determined at a required value. Thus, the FET Qis changed to its nonconducting state when the gate potential of the FETQ is at earth potential or zero potential. Further, the number of theabovementioned circuit arrangement shown in FIG. I which is installed inthe console of the instrument corresponds in number to the playing keys,for example, 61.

Now, the operation of the circuit as mentioned above will be describedhereunder.

When any one key K arranged in the electronic musical in strument isdepressed by the player, the normal keyer circuit S is operativepresenting a predetermined internal impedance to transmit a tone signalapplied at the input terminal R, to the output terminal T as a normalkeyed tone signal B having a predetermined level irresponsive to the keydepression intensity. At this time, a magnetic member (magnetized)attached to the key moves close to or away from a fixed coil L, therebyresulting in a damped 'altemating current voltage approximatelyproportional to the intensity or speed of depression of a playing keydue to a variation in interlinking fluxes established round the coil,the waveform of which is shown in FIG. 3. Theoretically this voltageshould be a DC impulse, but actually it becomes of the above-shownwaveform due to mechanical bouncing of the key and the associatedelements. The induced alternating current voltage is positivelyrectified by the element D and then the resulting positive DC impulsevoltage is applied to the parallel circuit of the capacitor C, and theresistor R, one end thereof being grounded. At the parallel circuit thewaveform of the DC impulse voltage is translated into an approximatesawtooth pulse signal having a magnitude according to the key depressionintensity as shown in FIG. 4 and the resulting pulse signal is'appliedto the gate of the F ET 0 and as a result, the F ET 0 is made in itsconducting state for a short period of timefor example, 0.1 to 0.5second immediately after the key depression, so that the input tonesignal having been applied to the source of the FET Q may be derived asa tone signal having an envelope of an abrupt buildup and a subsequentdecay or an attack signal immediately after the key depression. Thus, atthe output terminal T may be derived an output tone signal in which theattack sound signal A, in response to the key depression intensity ispartially superposed on the normal keyed tone signal B, of apredetermined amplitude irresponsive to the key depression intensity asshown in FIG. 5. In other words the normal keyed tone signal additivelyproviding the attack sound signal A, may be derived at the outputterminal T,,.

Now, the amplitude characteristics of the attack sound signal A may bevaried in accordance with the magnitude of a key depression speed asshown by several dotted curves in FIG. 5 in the various manners. Thevariation in the amplitude of the attack sound signal substantiallyprovides the same auditory effect as the amplitude of a tone output ofthe instrument is wholly varied to the audience of music being played.Thus, at the output terminal T an output tone signal having an amplitudesubstantially corresponding to the key depression intensity or speed maybe derived. However, when the key K is depressed quite slowly, the coilL does not induce any electromotive force or voltage, so that the FET Qis kept in its nonconducting state and of course, no attack sound signalA. is produced.

If the playing key is kept depressed, no further voltage is induced inthe coil L. Accordingly, the gate potential of the FET Q becomes atground potential after a required short period of time from the keydepression and hence, the FET Q is rendered to be in its nonconductingstate. Then, at the output terminal T there can be continuously derivedonly the normal keyed tone signal B, of a predetermined amplitude, whichis shown by a flat curve in FIG. 5, from the keyer circuit S being keyedby retaining the key depression, still release of the depressed key asshown in FIG. 5.

Upon release of the key being depressed, the key is made restored by itsself-return action and simultaneously, the keyer circuit S is made opento be in its nonconducting state, so that no output signal is developedat the terminal T As described above, in the circuit arrangement, notonly the amplitude characteristic of an output tone signal of theinstrument can be relatively varied substantially only by varying theamplitude of an attack signal in accordance with the key depressionintensity, but also the buildup amplitude of the tone signal can be mademore distinct to permit more ad vantageous playing of the instrument andto easily provide a so-called touch-responsive effect resembling that ofa piano.

Now, in the circuit arrangement, a conventional tone color circuit J maybe inserted between the drain of the FET Q and the output terminal T, asshown by a dotted line block in FIG. 1. For example, if the tone colorcircuit is adapted to emphasize the high harmonics of the tone signalits buildup amplitude characteristic or the starting of the gated tonesignal becomes more distinct and as a whole the tone color of the outputsignal can be varied with the decay of the attack sound, thus providinginteresting effects of music being played.

As a substitution of the coil L, magnetosensitive elements orpressure-sensitive electric elements may be used. Further, the FET usedhere may be substituted by other switching element such as a transistorof other types, diodes or vacuum tube etc.

Referring to H6. 2, there is shown another embodiment of the present ininvention. However, the arrangement is the same as that of FIG. 1 exceptthat the connection point r is connected via the resistor R to anotherinput terminal T to which another tone signal having a different footagenumber is applied from a different tone source circuit which isavailable and is not shown here, in place of the terminal T In this caseit will be understood that the instrument using the circuit provides anormal keyed tone signal having an attack sound signal A, of which theamplitude is varied in accordance with the intensity of depression of acorresponding playing key and of which the footage number (e.g., 4) isdifferent from that of a tone signal (e.g., 8) applied to the keyercircuit. Further, to the terminals T, and T tone signals having a samefootage number and different tone colors (or waveforms) may also beapplied. The operation and function and effect of the circuit accordingto the second embodiment should be understood in the same manner as inthe first embodiment and therefore, the details thereof have beenomitted.

l claim:

1. A touch-responsive keying system for an electronic musical instrumenthaving a plurality of keys and a tone generator, said system comprising:

a like plurality of voltage generating means, each being responsive tothe intensity of depression of a corresponding one of said plurality ofkeys for generating a voltage also responsive to the intensity ofdepression of said cor responding key,

a like plurality of keyer circuit means connected to said tonegenerator, each keyer circuit means being capable of producing a keyedtone signal having a predetermined amplitude irresponsive to thedepression intensity of a corresponding playing key, and

a like plurality of gate circuit means, each being connected to arespectively corresponding voltage generating means, to said tonegenerator and to a respectively corresponding keyer circuit means, eachof said gate circuit means being responsive to the level of saidgenerated voltage from the respectively corresponding one of saidvoltage generating means for developing a tone signal having an envelopepattern of abrupt buildup and sub sequent decay and which key depressionintensity responsive tone signal output is connected to combine with thepredetermined amplitude output of the respectively corresponding keyercircuit for the each of said plurality of keys.

2. A touch-responsive keying system according to claim 1,

in which the input of each of the gate circuit means is connected to theinput of the respectively corresponding keyer circuit.

3. A touch-responsive keying system according to claim 1. in which theinput of each of the gate circuit means is connected to a tone sourcegenerating a tone signal having a waveform different from that connectedto the input of the respectively corresponding keyer circuit means.

4. A touch-responsive keying system according to claim 1, in which eachof said gate circuit means includes an active element having a controlelectrode and first and second electrodes, said control electrode beingconnected to an output terminal of the respectively correspondingvoltage generating means, said first electrode being connected to a tonesource which is also connected to the input of the respectivelycorresponding keyer circuit means and said second electrode beingconnected to the output of said keyer circuit means.

5. A touch-responsive keying system according to claim 4, in which saidactive element is a field-effect transistor.

6. A touch-responsive keying system according to claim 1, in which eachof said voltage generating means includes a coil adapted to generate adamped AC voltage responsive to the actuation speed of a respectivelycorresponding playing key, a unidirectional conducting element forrectifying the AC voltage, and a circuit for translating the rectifiedvoltage into a pulse signal of an approximate sawtooth waveform.

7. A touch-responsive keying system as in claim 1 in which each of saidgate circuit means includes an active element having a control electrodeand first and second electrodes, said control electrode being connectedto an output terminal of the respectively corresponding voltagegenerating means, said first electrode being connected to a first tonesource having a first footage, the input of the respectivelycorresponding keyer circuit means being connected to a second tonesource having a second footage, and said second electrode beingconnected to the output of said keyer circuit means.

8. In an electronic musical instrument having playing keys and tonesources, a touch-responsive keying system for each of said playing keys,said system comprising:

an input terminal connected to a predetermined one of said tone sources.

an output terminal,

a keyer circuit means connected to said input terminal and said outputterminal for keying a tone signal from said tone source to said outputterminal with a predetermined amplitude irresponsive to the depressionintensity of said y;

voltage generating means for generating a voltage responsive to thedepression intensity of said key; and

a gate circuit means connected to said voltage generating means, to atleast one of said tone sources and to said output terminal fordeveloping a tone signal having an envelope pattern of an abrupt buildupand a subsequent decay with an amplitude determined by said voltage.

9. A touch-responsive keying system according to claim 8 in which saidgate circuit means has a tone signal input connected to said inputterminal for receiving a tone signal from said predetermined tone sourcein common with the input of said keyer circuit means.

10. A touch-responsive keying system according to claim 9 in which saidgate circuit includes a field-effect transistor having a gate electrode,a source electrode and a drain electrode, said gate electrode beingconnected to said voltage generating means, said source electrode beingconnected to said input terminal and said drain electrode beingconnected to said output terminal.

11. A touch-responsive keying system according to claim 9 in which thereis further provided a tone color circuit for emphasizing high harmonicsof the tone signal, said tone color circuit being connected between saidgate circuit means and said output terminal.

12. A touch-responsive keying system according to claim 8 in which thereis further provided a second input terminal connected to a tone signalinput of said gate circuit means which voltage generating means, saidsource electrode being connected to said second input terminal and saiddrain electrode being connected to said output terminal.

15. A touch-responsive keying system according to claim 8 in which saidvoltage generating means includes a coil adapted to generate a damped ACvoltage responsive to the depression speed of said key, a unidirectionalconducting element for rectifying said AC voltage, and a circuit fortranslating the rectified voltage into a pulse signal of an approximatesawtooth wavefonn.

l I II l

1. A touch-responsive keying system for an electronic musical instrumenthaving a plurality of keys and a tone generator, said system comprising:a like plurality of voltage generating means, each being responsive tothe intensity of depression of a corresponding one of said plurality ofkeys for generating a voltage also responsive to the intensity ofdepression of said corresponding key, a like plurality of keyer circuitmeans connected to said tone generator, each keyer circuit means beingcapable of producing a keyed tone signal having a predeterminedamplitude irresponsive to the depression intensity of a correspondingplaying key, and a like plurality of gate circuit means, each beingconnected to a respectively corresponding voltage generating means, tosaid tone generator and to a respectively corresponding keyer circuitmeans, each of said gate circuit means being responsive to the level ofsaid generated voltage from the respectively corresponding one of saidvoltage generating means for developing a tone signal having an envelopepattern of abrupt buildup and subsequent decay and which key depressionintensity responsive tone signal output is connected to combine with thepredetermined amplitude output of the respectively corresponding keyercircuit for the each of said plurality of keys.
 2. A touch-responsivekeying system according to claim 1, in which the input of each of thegate circuit means is connected to the input of the respectivelycorresponding keyer circuit.
 3. A touch-responsive keying systemaccording to claim 1, in which the input of each of the gate circuitmeans is connected to a tone source generating a tone signal having awaveform different from that connected to the input of the respectivelycorresponding keyer circuit means.
 4. A touch-responsive keying systemaccording to claim 1, in which each of said gate circuit means includesan active element having a control electrode and first and secondelectrodes, said control electrode being connected to an output terminalof the respectively corresponding voltage generating means, said firstelectrode being connected to a tone source which is also connected tothe input of the respectively corresponding keyer circuit means and saidsecond electrode being connected to the output of said keyer circuitmeans.
 5. A touch-responsive keying system according to claim 4, inwhich said active element is a field-effect transistor.
 6. Atouch-responsive keying system according to claim 1, in which each ofsaid voltage generating means includes a coil adapted to generate adamped AC voltage responsive to the actuation speed of a respectivelycorresponding playing key, a unidirectional conducting element forrectifying the AC voltage, and a circuit for translating the rectifiedvoltage into a pulse signal of an approximate sawtooth waveform.
 7. Atouch-responsive keying system as in claim 1 in which each of said gatecircuit means includes an active element having a control electrode andfirst and second electrodes, said control electrode being connected toan output terminal of the respectively corresponding voltage generatingmeans, said first electrode being connected to a first tone sourcehaving a first footage, the input of the respectively correspondingkeyer circuit means being connected to a second tone source having asecond footage, and said second electrode being connected to the outputof said keyer circuit means.
 8. In an electronic musical instrumenthaving playing keys and tone sources, a touch-responsive keying systemfor each of said playing keys, said system comprising: an input terminalconnected to a predetermined one of said tone sources. an outputterminal, a keyer circuit means connected to said input terminal andsaid output terminal for keying a tone signal from said tone source tosaid output terminal with a predetermined amplitude irresponsive to thedepression intensity of said key; voltage generating means forgenerating a voltage responsive to the depression intensity of said key;and a gate circuit means connected to said voltage generating means, toat least one of said tone sources and to said output terminal fordeveloping a tone signal having an envelope pattern of an abrupt buildupand a subsequent decay with an amplitude determined by said voltage. 9.A touch-responsive keying system according to claim 8 in which said gatecircuit means has a tone signal input connected to said input terminalfor receiving a tone signal from said predetermined tone source incommon with the input of said keyer circuit means.
 10. Atouch-responsive keying system according to claim 9 in which said gatecircuit includes a field-effect transistor having a gate electrode, asource electrode and a drain electrode, said gate electrode beingconnected to said voltage generating means, said source electrode beingconnected to said input terminal and said drain electrode beingconnected to said output terminal.
 11. A touch-responsive keying systemaccording to claim 9 in which there is further provided a tone colorcircuit for emphasizing high harmonics of the tone signal, said tonecolor circuit being connected between said gate circuit means and saidoutput terminal.
 12. A touch-responsive keying system according to claim8 in which there is further provided a second input terminal connectedto a tone signal input of said gate circuit means which second inputterminal is connected to a different one of said tone sources.
 13. Atouch-responsive keying system according to claim 12 in which there isfurther provided a tone color circuit for emphasizing high harmonics ofthe tone signal, said tone color circuit being connected between saidgate circuit means and said output terminal.
 14. A touch-responsivekeying system according to claim 12 in which said gate circuit meansincludes a field-effect transistor having a gate electrode, a sourceelectrode and a drain electrode, said gate electrode being connected tosaid voltage generating means, said source electrode being connected tosaid second input terminal and said drain electrode being connected tosaid output terminal.
 15. A touch-responsive keying system according toclaim 8 in which said voltage generating means includes a coil adaptedto generate a damped AC voltage responsive to the depression speed ofsaid key, a unidirectional conducting element for rectifying said ACvoltage, and a circuit for translating the rectified voltage into apulse signal of an approximate sawtooth waveform.